oliver



Oct. 23, 1928. 3,688,938

J. R, OLIVER SEWING MACHINE Filed April 6. 1926 2 Sheets-Sheet 1 ATTORNE YS.

Oct 23, 1928. 11,688,938 J. R. OLIVER SEWING MACHINE Filed April 1926 2Sheets-Sheet 2 I '57 h 1' /6 w 25 4/ I .1 I C x 6 x2 5 QQW KWQD tQWM ATTORNE VS.

atentecl act.

Ui ll'l itlll) s t en ASSTGNOR TO REECE SHOE CORPGB-EIOII OE MAINE.

SERVING TEASE-ZINE.

Application filed April 6,

This invention relates to sewing machines and more especially to thecontrol or regulation of the thread and the application of tensionthereto. Tn the particular form 8 herein illustrated the invention isparticularly adapted to use on shoe stitching machines or similarleather sewing machines using wax thread; for example the shoe stitchingmachine well known as the weltandturn machine, represented for exampleby the Reece welt-and-turn machine illustrated in Patent Number1,288,366 of December l'Z, 1918 and subsequent patents and pendingapplications, such machine producing chain stitches by the use ofcurved, hooked needle and cooperating instruments; although the novelfeatures are applicable to other types of shoe or leather stitchingmachines, or other sewing machines.

The general object of the present invention is to improve the handlingof the thread in such machines and especially to improve the operationand efiiciency of the thread tension control mechanism. A specific obloleet is to provide automatic means for causing the relaxing orsubstantial release of the tension upon the thread at a certain periodin the stitch cycle and in an effective and accurate manner. A furtherobject is to provide a simple and smooth acting mechanism for suchpurposes. Further objects and advantages of the presentinvention will beexplained in the hereinafter following description of an illustrativeembodiment thereof, or will be apparent to those skilled 'in the art. Tothe attainment of the objects and advantages referred to the presentinvention consists in the novel sewing ma chine and the novel featuresof combination, arrangement and structure herein illustrated ordescribed.

In the accompanying drawings Fig. 1 is a partial right hand elevation ofa weltand-turn stitching machine, showing suitcient of the exteriorparts of the machine to aiford an explanation of the present invention.

Fig. 2 is an opposite or left hand elevation of the same taken partly insection on the U line22 of Fig. 3.

Fig. 3 is a top plan view showing the main elements particularlyconcerned with the present invention.

Fig. l is a front elevation and central Serial No. 100,088.

section of certain of the parts shown in Fig. 5 is a diagram showing theaction or movement of certain of the elements, and the coordinationthereof with the movements of the needle, looper, take-up and other sualinstruments concerned in the forman of stitches.

The cycle of stitching operations in a welt-and-turn stitching machinemay be sub- .tantially as indicated in the diagram in said prior patent,showing the movements of the needle, the looper, the take-up and otherinstruments. Fig. 5 herein shows the movements of the needle, looper andtakeup as I prefer to operate them, and as indicated in pendingapplications of mine. Thus the needle may be in advancing motion ithepart of the diagram marked ater retracting at 0 The take-up may wing ina manner to give thread during the movement 7, and moving reversely at fvill take up the thread, in cooperation With the needle movements. Thelooper moves to advance adjacent to the needle and thereafter movearound the needle so as to place a loop in the barb thereof. Themovement of the looper advancing to the needle and drawing thread fromthe supplv is indicated at d, while in the movement (Z the thread isbeing engaged with the needle hook. The usual feed device may advancethe work at curved part 9.

According to the present invention the operation of such a machine isimproved by complete release or relaxation of the thread tension duringthe period in which the looper is advancing toward the needle andpulling thread from the supply. At this period in the cycle the threadis apt to real; and this invention obviates the chiliculty preferably bya complete removal of the tension. The mechanism and action foraccomplishing this result will next be described in connection with thediagram of Fig. and the other figures of the drawings.

The vertical frame walls 10 and 11 may be he left and right wallscorresponding to those shown in the prior patent and applications. Themain or stitching shaft 12 has suitable connections to the needle,looper, take-up, etc, such connections including for xample a crank 13formed on the shaft 12. The shaft is journalled in a bearing 14 in theframe wall 11 and may be Similarly jour naled near its other end. Thefixed parts 0 the machine may include a bearing stud 1 which isshouldered and passes through a collar or lug 16 spacing it from theleft wall 10, to which the stud is secured by screw threads indicated inl.

The matter of applying the tension to the thread may be through agrooved thread wheel 17 which is shown mounted to turn freely on thestud 15. As usual the thread may make substantially a complete turnabout the wheel, the thread wheel having a friction face or flange 1 andfelt washer or facing 18 by which frictional pressure may be applied toretard or brake the rotation of the thread wheel and thus apply tensionto the thread. A pressure disk 19 is arranged loosely on the stud in aposition to bear against the friction flange 17 of the thread wheel, orrather the friction facing 18 thereof. For purposes later to bedescribed the pressure disk 19 is provided with peripheral ratchet teeth19. Resilient pressure is preferred but instead of applying thisdirectly against the pressure disk 19 the following special arrangementis shown, constituting a feature of the present invention. The pressureshank or rod 20 has mounted at its left end a pressure ring 20' which isconstantly thrust to the left, but with a thrust bearing or rollingelement 20 between the pressure ring 20 and the pressure disk 19.Ordinarily this would impose no resistance to the rotation of the threadwheel, but when the disk 19 is anchored against rotation the frictionalbraking action upon the thread wheel is put into force, as will bedescribed.

The pressure shank 20 is shown as extending through the frame right wall11, its outer end provided with a forked head 21. The shank or rod 20 isshown surrounded by a threaded sleeve 22 which engages threads in theframe wall 11 and is provided with an exterior head 23 by which thesleeve may be turned so as to adjust it longitudinally and regulate thenormal degree of tension or spring pressure on the thread wheel. Thetension spring 2% surrounds the shank 20 between the elements 20" and22. This spring is under constant compression and presses leftwardagainst ring 2O which in turn, through the antifriction bearing 20,applies pressure to the disk 19, thrusting toward the thread wheel. Anexterior hand lever 25 is shown in Fig. 1 which may be swung to pulloutwardly upon the pressure shank 20 and thereby release the tension atwill. An automatic release of the tension when the needle is retractedand the work is being fed along may be effected through the followingmechanism, described in copending application, and per se forming nopart of the present invention. A rock lever 26 is against its head 21.Vhen the rock lever is swung outwardly this moves the shank and releasesthe tension. The swinging lever 26 has upstanding ears 30 and 31 throu hwhich is engaged a pin adapted to e pushed or pressed to the right byswinging the lever 26. The actual swinging movement may be very slightin order to release the tension for the purposes stated. For thispurpose a push rod 37 is shown having a slotted outer extremity, theslot engaging the push pin 32. This motion may be effected through aneccentric by the following mechanism. A large helical gear 39 is shownmounted on the main shaft 12. This engages a helical gear 40 arranged ona short shaft ll set at right angles to the main shaft and supported infront and rear bearings 42 and 43. The ratio of the gears may be one toone so that the gear 40 makes one rotation for each turn of the mainshaft, corresponding with a stitching cycle. At the front side of thegear 10 is shown an eccentric l lengaged by a strap l6 united with thepush rod 37, so that the operation of the eccentric may cause therelaxing of the tension at a point corresponding with the termination ofa stitch cycle. Instead of laving this relaxation of the tension occurin every stitch cycle it is sometimes sufficient to omit it except atthe end of the final stitch cycle when stopping themachine, thuspermitting the work and thread to be drawn away from the machine. Thisit is proposed to accomplish by a particular arrangement between thethrust rod 37 and the eccentric 441C, for example a roller instead of astrap at the end of the thrust rod, with a pedal connection moving theroller into the path of the eccentric when the pedal is let up to stopthe machine, so the rod will swing lever 26 and remove the pressure.

The pressure disk 19 intermediate the tension wheel flange 17 and thepressure ring 20 has been referred to as provided with ratchet teeth 19faround its periphery. Under the normal condition of the tension theintermediate disk 19 is anchored by means of the ratchet teeth and apawl 55, which howeveris shown lifted or disengaged in Fig. 2. hen thepawl is engaged against a ratchet tooth the intermediate disk 19 isprevented from rotation. It therefore imposes resistance to the threadwheel, under the pressure of the tension spring 2%. The lifting of thepawl wholly releases the resistance, that is substantially so, thecollar 16 being preferably of antifriction metal, and the disk 19 beingengaged by a roller hearing.

The pawl 55 is shown attached to a short rockshaft 56 mounted inbearings 57 above the tension devices, with a special bracket 58 holdingthese parts. For the purpose of lifting and lowering the pawl at theproper points of time there is shown a rocker arm 59 on the rock shaft56, the extremity of this arm having finger 60 which extends downwardlyinto the path of a lifting pin or contact 61 mounted at the rear face ofthe gear 40. As the rotation of the gear brings the pin 61 toward itsupper position the pin will contact and lift the lin er 60 and thusraise the pawl and release the tension, while as soon as the revolvingpin pas es from under the finger 60 the pawl will be dropped in positionto engage the shoulder of the next ratchet tooth.

The preferred timing of the described parts, and the resulting action,may be described in connection with the diagram Fig. 5, which hasalready been described in relation to the movements of the needle,take-up and looper. While the looper is moving along the path cl andapproaching the needle it is drawing thread from th supply, and itisdesireo to release the tension for this portion of the cycle, as alreadyexplained. About the t me this thread pulling movement of the loopercommences the pawl 55 is to be lifted from the ratchet. The path m onthe diagram shows the position of the pawl engaged upon the ratchet. Thepath m indicates the lifting of the pawl by the finger 6i, and it willbe seen that this immediately precedes the thread pulling movement ofthe looper. The pawl is thenlowered or restored along the path 00 butdoes not become effective to lock the ratchet and thus apply fulltension, until contacting the next ratchet tooth, indicated at :0 on thediagram, the looper at this time having finished its thread pullingmovementand being about to lay he bread on the barb of the needle.

As the lifting pin lifts the finger and pawl, the thread then beingunder tension, the thread wheel will at once move freely forward by thethread pull, so that the finger can be immediately dropped upon the nextratchettooth. Each tooth is preferably of such length as to correspondwith the amount of rotation of the thread wheel necessary to supply thethread pulled by the looper, so that the tension is released during suchthread-pulling movement, the pawl then coming into contact with the nexttooth shoulder and applying the full tension.

This all occurs when the needle is forward,

through the work, and the full tension, sus pended for part of thelooper movement, is reapplied before the take-up and stitch settingoperations occur.

It will be understood that in the welt-andturn stitching machine, forwhich the illustrated embodiment is especially designed, the needle is acurved hook needle which penetrates the work on its advance stroke andat its advanced position is supplied with a loop of thread by themovements of the looper, the needle then retracting, and being near itsfully retracted position when the work is fed by the usual or other feedmeans. The general operation of the present invention is to relax orrelease the tension while the looper is pulling thread from the supplyto apply to the needle, and fully restoring tension th subsequenttake-up action; stated in anolher way the tension resistance issuspended to fat ate the looper movement. It will be noticed that theremoval of the tension is not merely for a. predetermined part of thecycle in point. of time, but is during the pulling by the looper of apredetermined length of threat. 'lhe ratchet wheel is designed withteeth of length corresponding with the thread pulling movement of thelooper. When the pawl is lifted from the ratchet the thread wheel isreleased but the pawl is restored on top of the next tooth. As soon asthe looper has pulled the prer eterminetl amount thread, this, throughthe turning of t' thread wheel, and the ratchet wheel, brings the intooth shoulder up to the pawl, and thus tern-rm ates the suspension ofthe tension resistance, Thus as staled the removal of tension is for apredetermined length of thread drawn. In practise the ratchet teeth maybe caused to meet the pawl slightly before the looper has completed itsthread drawing inoven'ient, as a slight stretching of the thread can beallowed for. Another point of novelty involved in the presen inventionis that the tension is released without the withdrawing or relaxing ofthe spring pressure. This is due to the fact that the friction member ordisk 19, while constantly subjected to the pressure of the tensionspring, is able to be anchored or locked to a stationary part, to imposefriction on the thread wheel, or rendered free to remove the tension.The friction dish is squeezed between the thread wheel and the pressuremember or ring, with an antifriction device or ball bearing between thedisk and ring. In one sense the friction disk is a revoluble brake whichis normally anchored, locked, or held against rotation so as to imposefrictional resistance upon the thread wheel, or to be rendered free orre leased for rotation to remove the resistance. By a ratchet, inconnection with the friction disk, is intended any equivalentscries ofteeth or projections cooperating with a suitable pawl or dog which maybe applied to and removed from the teeth.

There has thus been described a sewing machine, of the class referredto, embodying the principles and attaining the objects of the presentinvention; but as various matters of combination, arrangement andstructure with su stantial fri *tion, a nonre oluble pres cr men'iber pis l friction membcr against the thread wheei, with an antil rict-ionrolling-clement caring between the presscr member and triction member,means anchorii g the friction member against rotation during part ofeach stitch cycle to impose full resistance on the thread wheel and fulltension on the thread, and timed means operating to release the frictionmem. b r thereby to relax the tension during another part of each stitchcycle.

2. In a hook needle sewing machine, a revoluble thread wheel, arevoluble lining member contacting the thread wheel, means constantlypressing said friction member toward the thread wheel, means foranchoring and releasing the friction member comprising tooth projectionsaround the friction member spaced according to t 1e length of thread tobe pulled in each cycle, and a dog arranged to enagage said teeth toanchor the friction member, and to disengage and reengage the same topermit a given length of thread to be pulled from the supplycorresponding with the tooth spacing, and timed means controlling saiddo 23. A sewing machine as in claim 2, and wherein the friction memberteeth constitute a ratchet having individual teeth of an ex" tentcorresponding to the required length of tin-cad to be pulled during therelease of tension, and the dog controlling means acting to lift the dogfrom a tooth at the commencement of the pulling action and drop it uponthe teeth, the tooth-extent determining the length of thread pulled.

4. in a hook needle sewing machine, a revoluble thread guide, a frictionmember constantly pressed against the guide, means normally anchoringthe friction member and imposing full tension on the thread, and timedmeans operative during the pulling of thread from the supply forreleasing the friction member and thereby suspending the tension for apredetermined length of thread pulled, comprising a ratchet each toothof which corresponds in length with the thread to be pulled, a pawl, andtimed means for shitting the pawl from one tooth to the next tooth.

5. in a hook needi sewing machine, a thread wheel having non-slippingengagement with the thread, friction means normall; imposing highresistance upon the thread wheel, and timed means relaxing suchresistance for the thread drawing action and i toring such resistancealter a predetermined length of thread has been drawn, comorisin aratchet each tooth of which cor- ZZ) ponds in lent-h With the thread tobe pulled, a pawl, and timed means for shittmg the pawl from one toothto the nor tooth. I

in testnnony whereof, I have attired my signature hereto,

JOHN ROGER OLIVER.

